1. Field of the Invention
The present invention relates to a lamp circuit for automobiles, more particularly, to the achievement of reduction in the number of electrically functional parts used in the lamp circuit, thereby achieving a reduction in the amount of wiring, by simplifying the circuit while maintaining the function of lamp circuit.
2. Description of the Related Art
In automobiles to be used in northern Europe, the lamps of the automobiles are required to light up even in the daytime due to a longer time interval of dim sunlight. Therefore, automobiles intended for destination to such areas adopt a specific lamp circuit, so called xe2x80x9cDRLxe2x80x9d (Daytime Running Light) which lights up a low beam lamp in the headlamp when the engine operates with the ignition switch being ON.
FIG. 2 shows a lamp circuit 1 which corresponds to the conventional DRL, and the above-mentioned lamp circuit is provided with a DRL controller 2, a lamp switchbox 3, a head lamp relay 4, a DRL relay 5, right/left low beam lamps 6a and 6b in the head lamp, and right/left high beam lamps 7a and 7b, in the head lamp.
In the above-mentioned DRL controller 2, circuits are incorporated for a tail lamp ON signal from lamp switch box 3, a light up signal of head lamp, a passing signal, and a high-side switching signal are entered; and an ON signal of the ignition switch 8 and engine operation signals of the signal output component 9 can be entered.
In addition, the DRL controller 2 is programmed so that it properly closes a lamp light ON contact point 2a and High/Low switching contact point 2b, when these types of signals are received and consequently drop the above-mentioned contact points to an OV (ground level).
DRL illumination of the above-mentioned lamp circuit 1 is carried out by running the engine with the ignition switch 8 turned ON and entering an ignition ON signal and an engine operation signal to a DRL controller. On receiving the above-mentioned signal, a circuit is set up with a coil 4b provided between a battery B and a head lamp relay 4 by closing the lamp illumination contact point 2a by the DRL controller 2, the relay contact point 4a is closed by the coil 4b being energized, while in a DRL relay 5, a low-side contact point 5a is closed because of the coil 5c has not been energized. Thus, with the closed connection of these respective contact points, the battery B causes left/right low beam lamp 6a and 6b to be illuminated.
In order to illuminate the left/right high beam lamps 7a and 7b, a head lamp switch 3a of switch box 3 is connected with a head lamp contact point 3e, and high/low switching switch 3c is connected with a high side contact point 3g, whereby the head lamp light-up signal and high-side switching signal are entered into the DRL controller 2. With this input signal, the DRL controller 2 closes the high/low switching contact point 5b by energizing the coil 5c. With these actions, the battery B and left/right high beam lamps 7a and 7b are connected, which consequently causes the above-mentioned lamps to be illuminated.
In this case, the illumination of lamps other than as mentioned above can also illuminate the tail lamps and interior night lighting (not illustrated here), and can also illuminate low beam lamps 6a and 6b as well as illumination of the above-mentioned tail lightening without connecting the high/low switching switch 3C to the high side contact point 3g. In addition, by connecting a passing switch 3b with a passing contact point 3f, the high beam lamps 7a and 7b can be illuminated in a passing mode.
The illumination described above is performed in such a manner that, other than illumination of the DRL, the illumination in this case is made possible without regard to switching ON/OFF of the ignition switch 8 in consideration of safety, etc.
In order to carry out control of the DRL, a lamp circuit 1 which complies with the above-mentioned DRL uses an additional number of electrically functional components, such as DRL relay 5 and a circuit for the relay, compared with those of normal illumination lamp circuits.
Therefore, there are the problems of additional expenses for the above-mentioned relay, circuit, etc., and the number of processes required for circuit manufacture will also increase. Furthermore, the space required for housing the circuit becomes larger, and weight also increases. In addition, an exclusive relay block for connecting the above-mentioned relay, etc., becomes necessary, which may also increase the factor of cost.
The present invention was made in view of the above-mentioned problems, with the aim of achieving cost reduction and weight reduction by decreasing the number of circuits and electrically functional components, by revising the present condition of lamp circuits for automobiles complying with DRL requirements.
In order to solve the above-mentioned problems, one aspect of the present invention provides a lamp circuit for automobiles, which complies with DRL illumination for a low beam lamp and a high beam lamp in head lamp, wherein, the lamp circuit is provided with a DRL controller, a lamp switch box, a relay, at least one low beam lamp, at least one high beam lamp, an ignition switch, an engine operation signal output component, and a battery.
The above-mentioned relay is provided with a common contact point, two contact points that are normally open, and two coils. The common contact point is connected with the battery, and one of the above-mentioned two contact points is connected with the low beam lamp, the other connected with the high beam lamp, respectively, and the two coils are connected with the DRL controller.
The DRL controller is connected in such a manner that respective signals from the lamp switch box, the ignition switch, and the engine operation signal output component are entered, so that, in a first condition, the contact point connected with the low beam lamp is closed and the DRL is illuminated, as a result of energization of one of the two coils of the above-mentioned relay, when signals from the ignition switch and the engine rotation signal output component are entered to the DRL controller.
In a second condition, the other one of the two coils of the above-mentioned relay becomes energized according to a signal when a signal from the lamp switch box is entered to the above-mentioned DRL controller, and the other of the at least one low beam lamp and the at least one high beam lamp is illuminated as a result of closing the above-mentioned relay which corresponds to the other coil.
In this way, the use of a relay having two coils at two contact points in a lamp circuit which complies with the DRL light-up has replaced the components in a circuit, which have conventionally been composed of a head lamp relay and a DRL relay, with a single relay while maintaining the same function as the conventional ones. Accordingly, this allows the number of relays, electric functional components, and circuits to be reduced. In addition, along with the reduction of components, the costs required for the circuits as well as weight and the like can also be decreased.
The above-mentioned relay having two coils allows proper switching between DRL high beam illumination and normal illumination by switching two contact points with respective coils energized by entering each type of signals. In addition, if the above-mentioned two coils are not energized, it is not possible to illuminate the low beam lamp, etc., because the circuit is shut off when the electric power source is at an OFF condition, because the two contact points have a middle neutral position at which both contact points come to an open position simultaneously.
In another aspect of the present invention, a lamp circuit which provides a DRL illumination for a vehicle is provided that includes at least one low beam lamp and at least one high beam lamp, a controller, a lamp switch box, a switching mechanism, an ignition switch, an engine rotation signal output component, and a battery.
The switching mechanism is provided with a common contact point, first and second contact points which are normally open, a movable connecting piece connected to the common contact point, and operating mechanism for moving the connecting piece from a neutral position to a selected one of the first contact point and the second contact point. The common contact point is connected with the battery, one of the first and second contact points is connected with the at least one low beam lamp, the other of the first and second contact points is connected with the at least one high beam lamp, respectively, and the operating mechanism is connected with the controller.
The controller is connected in such a manner that respective signals from the lamp switch box, the ignition switch, and the engine rotation signal output component are entered in the controller, the connecting piece is connected with the first contact point and one of the at least one low beam lamp and the at least one high beam lamp as a result of actuation of the operating mechanism of the switching mechanism, when signals from the ignition switch and the engine rotation signal output component are entered in the controller to thereby illuminate the DRL, and the operating mechanism of the switching mechanism is actuated according to the signal when a signal from the lamp switch box is entered to the controller to connect the connecting piece to the second contact point, and the other of the at least one low beam lamp and the at least one high beam lamp is illuminated.
In other aspects of the invention, the lamp circuit may include at least two low beam lamps, or at least two high beam lamps, or at least two low beam lamps and at least two high beam lamps. Furthermore, the controller may include a DRL controller, the switching mechanism may include a relay, and the relay may include first and second coils, the first coil being energizable to move the connecting piece to engage the first contact point, and the second coil being energizable to move the connecting piece to engage the second contact point.